...mkdir /thdrive
...camcontrol rescan all
...mount_msdosfs /dev/da0s1 /thdrive
(....Expected error "no such file or directory" or "invalid argument")
...mount_msdosfs /dev/da0 /thdrive
(...Same expected error(s)) (the other one of the one which first appears)
....mount_msdosfs /dev/da0s1 /thdrive
SUCCESS.

Note the first and third mount commands are the same.
I forget if mount_msdosfs is deprecated or not
same OS, _6, on 2 different laptops, same thumbdrive
Tip maybe useful for usb hard drive mounting, etc. esp. if one
keeps getting the same two errors repeatedly

__________________FreeBSD 12.0-CURRENT

Last edited by jb_daefo; 11th November 2008 at 03:27 AM.
Reason: re-edited it good. Text disappeared. Re-edited it so-so.

This sort of thing is a side-effect of things like U3-enabled disks. The actual node doesn't show up until the device is 'kicked'. I think that it is the programming in the device itself that is causing it.
If you have a U3-enabled drive, I recommend you use the utility to strip the U3-good/badness out of it. (Back up your data first, as the utility also wipes the drive!!)
If you don't have a U3-enabled drive - Keep it that way!

__________________The only dumb question is a question not asked.
The only dumb answer is an answer not given.